Switch mechanism for attachment plugs



Sept. 13, 1932.' L. LUDWIG swITcH MECHANISM FQR ATTACHMENT PLUGS Filed Feb. 9. 1951 INVENTOR ATTO Patented Sept. 13, 1932 LOUISLUDWIG, 0F BROOKLYN, NEVI YORK 'i SWITCH MncrrANrsM non 'ATTACHMENT rLUGs Appneation nea February 9, 1931. serial No. 514,402.

The invention relates to switches employed in electric attachment plugs. While 1 am aware that the prior art shows many attachment plugs in which switches are employed, the present invention resides in the improved constructionl oit the switch and aims to overcome the defects generally found in these and to provide a switch mechanism ot simpler and 'moreV rigid design, which occupies less space, has a quicken action, and which can be manufactured at a lower cost.

Inthe switches now used, a separate frame is generally provided for supporting the switch arm and the operating lever, or, ii such frame is omitted, the stud on which these parts operate is unsupported at one end. This causes a strain which soon maires the switch inoperative. ln the present invention, I not only omit the extra frame, but ef fectively support the stud'at both ends, thus greatly prolongingr the life of the mechanism.

Furthermore, by employing a compression instead of a tension spring to operate the switch, I can use an operating lever constructed of a single piece ot insulating material instead of a metal lever tipped with a finger grip, as is now used. This attached inger grip generally works oti after the switch has been in use a short time.

Finally, by constructing the switch mechanism in the manner hereinafter shown and described, the attachment plug can be made in a single width Jfor itswhole length and not with an increased width across the switch chamber, as is now the case. This is an important feature, particularly when the attachment plug is used on a sad iron.

These and other advantages will be fully explained in the following description and in the accompanying drawing oii a preferred embodiment of the invention, in which Fig. 1 is a plan view oi an attachment plug having one of the half-casings removed and showing my improved switch mechanism,

Fig. 2 a similar view showing the switch in another position,

Fig. 3 a side view shown partly in section, and v Fig. 4 a sectional view talen on line L1-1 in Fig. 2.

The drawing showsv the hal-casings 10 and 11 in which are nested the regular, prong-engaging clamps 12 and 13 as well as the terminal screws 14; and 15. T he clamp 12V is connected to the terminal screw 141 by the lead 16, while the clamp 13 is connected to the terminal screw 15 by means ot the leads 17 and 18 which also form the switch blades between which the switch arm enters. 1Wires 19 and 20, contained in the cord 21, are connected to the terminal screws. Y

rEhe invention resides in the switch mechanism which is now to be described. 1t consists of a stud 22 which is molded in the casing 10 and on which the ill-shaped switch arm 23 and the operating lever 24 are mounted. The operating lever, which is made in one piece withthe serrated linger grip 25, is constructed of insulating material with a hole 26 at itsother end.Y 1t is inserted between thelegs oi the switch arm. A compression spring 27 has one end engaged in the hole 26 and the other end guided. on a tongue 28 formed on the switch arm. fr short thread is cut on the stud 22 and a nut 29 holds the operating lever and the switch arm in place. The end of: the stud is supported in a bearing 30 molded in the half-casing 11. Stops 31 and 32, which are molded in the casings, limit the movement of the switch arm.

From the foregoing it will be seen that the stud is eiectively supported at both ends and that, owing tothe narrow construction of the switch, the attachment plug may be made of a single width clear up to the neck 38. All the attachment plugs now in use are of greater` width at the part containing the switch chamber, as is indicated by the dotted lines 34, in Fig. 3. This increased width is a' disadvantage when the attachment plug is used in a sad iron as these irons are ordinarily made to rest on the so-called heel. When in this position the weight of the iron rests partly on the attachment plug and tends to i break it or else cause the prong-engaging clamps to become loosened. Y

lt willfbe seen that I have succeeded in providing a switch mechanism which has many advantages over the devices now in use.

Having' described my invention and its adand provided vantages, what I claim as new and wish to protect by Letters Patent is:

1. In a switch mechanism for attachment plugs of the class described, a stud having` one end secured in one of the half-casings and the other end supported in the other halfcasing of which the attachment plug is formed, a single U-shaped switch arm mount` ed on said stud, an operating lever mounted on said stud and engaged between the legs of the switch arm, and a spring connected between the operating lever and the switch arm for actuating the switch arm when theoperating lever is moved, the free end of the switch arm engaging between the switch blades formed by the flexible ends of the lead which connects one of the wire conductors with one of the contact members contained in the casing.

2. In a switch mechanism for attachment plugs of the class described, a stud having one end secured in one oi the half-casings and the other end supported in a bearing formed on the other half-casing of which the attachment plug is formed, a single U-shaped switch arm mounted on said stud, an operating lever mounted on said stud and engaged between the legs of the switch arm, and a compression spring connected between the operating lever and t-he switch arm for actuating the switch arm when the operating lever is moved, the free end of the switch arm engaging between the switch blades formed by the iieXible ends of the lead which connects one of the wire conductors with one of the contact ymembers contained in the casing.

3. In a switch mechanism for attachment plugs of the class described, a stud having one end secured in one of the half-casings and the other end supported in a bearing formed on the other half-casing of which the attachment plug is formed, a single U-shaped switch arm mounted on said stud, an operating lever mounted on said stud and engaged between the legs of the switch arm, said operating lever constructed from a single piece of insulating material, and a. spring connected between the operating lever and the switch arm for actuating the switch arm when the operating lever is moved, the free end of the switch arm engaging between the switch blades formed by the flexible ends of the lead which connects one of, the wire conductors with one of the contact members contained in the casing.

4. In a switch mechanism for attachment plugs oit the class described, a stud having one end secured in one of the halt-casings and the other end supported in a bearing formed on the other half-casing of which the attachment plug is formen, a single U- shaped switch arm mounted on said stud, an operating lever mounted on said stud and engaged between the legs of the switch arm,

means provided on the stud for preventing the part-s mounted thereon from being displaced from the half-casing in which the stud is secured when the other half-casing is removed, and a spring connected between the operating lever and the switch arm for actuating the switch arm when the operating lever is moved, the free end of the switch arm engaging between the switch blades formed by the flexible ends of the lead which connects one of the wire conductors with one o1" the contact members contained in the casing.

5. In a switch mechanism for attachment plugs of the class described, a stud having both its -ends securely supported in the halfcasings of which the attachment plug is formed, a single U-shaped switch arm mounted on said stud, an operating lever also mounted on the stud and engaged between the legs of the switch arm, and a spring connected between the operating lever and the switch arm for actuating the switch arm when the operating lever is moved, the free end of the switch arm engaging between the switch blades formed by the iiexible ends of 'the lead which connects one of the wire conductors with one of the contact members contained in the casing, the whole switch mechanism being of such space-saving construction that casings of the attachment plug may be constructed in one width throughout their entire length.

6. In la switch mechanism for attachment plugs of the class described, a stud secured 1n one of the half-casings of which the attachment plug is formed, a single U-shaped switch arm mounted on said stud, an operating lever mounted on said stud and engaged between the legs of the switch arm, and a spring connected between the operating lever and the switch arm for actuating the switch arm when the operating lever is moved, the free end of the switch arm engaging between the switch blades formed by the iexible ends of th-e lead which connects one of the wire conductors with one of the contact members contained in the casing.

LOUIS LUDWIG. 

